The present invention generally relates to air-cooled high speed electrical generators with integral blowers.
Compact high-power generators are desirable for many aircraft applications. Proper cooling of such generators is made challenging as evolving design requirements for such machines have resulted in increasingly smaller and more compact generators. High-power-density generators may require high pressure head to push cooling air through narrow cooling paths. Integrated centrifugal blowers attached directly to a generator shafts are often employed for cooling such generators. While centrifugal blowers may provide high pressure rise with high efficiency, they typically have radial exits. Thus output from these centrifugal blowers may not be aligned with cooling paths in the generator, many of which may be oriented axially. Output flow may be changed to an axial direction with a radial-to-axial diffuser. However such diffusers take up space in a generator and may produce significant pressure loss when employed in small spaces of a compact generator.
As can be seen, there is a need for a compact high-speed generator in which pressurized cooling air may be directed axially into cooling paths of the generator without use of a radial-to-axial diffuser.